Pandia Search Engine News blog has a nice review review of two new vertical search engines for health information: Healia and Kosmix
Here is a short summary:
* info comes from 8000 sites
* results could be vertically limited to causes, risks, symptoms, diagnosis, tests and treatment.
* there is additional results limitation by females, males, basic or advanced reading, etc
*info comes from entire web ( journals and blogs too) and selected sites
*results could be vertically limited to ones with basic info, or causes, symptoms, treatments
* there is a special section for alternative medicine, diet, nutrition and fitness
*users can propose sites to be added to the engine
Pandia also gives you a list with alternative search engines.